1. Field of the Invention
The present invention addresses the need for a plug-in hybrid electric vehicle and the control of the power for the vehicle.
2. Discussion of the Related Art
There is a need to reduce emissions and increase fuel economy or gas mileage from conventional internal combustion engine vehicles. In response to these needs, hybrid electric vehicles (“HEVs”) have been developed that incorporate an electric drive system typically in combination with a smaller internal combustion engine and a generator. HEVs offer some advantages but still require the internal combustion engine to operate, usually even on shorter trips. The fuel economy of HEVs is improving, but there remains a need for vehicles with even greater fuel economy, further reduced emissions and vehicles that do not need to use the internal combustion engine for short and longer trips.
Plug-in hybrid electric vehicles (“PHEVs”) offer an improvement over HEVs since they have an increased electric only range, increased fuel economy and reduced tailpipe emissions. Known PHEVs include separate AC chargers and separate DC/DC converters to provide the desired plug in functionality. Often, an additional power pack or battery is included in the PHEV. PHEVs charge the battery, provide power from the battery to the HEV and desirably capture surplus power from the HEV.
Known PHEV configurations include a cascade configuration which employees at least two inductor coils (usually at least three inductor coils) for the needed power management functions. Other limitations of this known configuration include increased weight, increased cost and increased space for the plug-in converter equipment.
There is a need and a desire for a simple stable converter design with a reduced number of large, heavy and costly components while offering safe and reliable functionality.